中国物理B ›› 2024, Vol. 33 ›› Issue (1): 17403-17403.doi: 10.1088/1674-1056/ad0145

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Majorana tunneling in a one-dimensional wire with non-Hermitian double quantum dots

Peng-Bin Niu(牛鹏斌)1,† and Hong-Gang Luo(罗洪刚)2,3   

  1. 1 Institute of Solid State Physics, Shanxi Datong University, and Shanxi Provincial Key Laboratory of Microstructural Electromagnetic Functional Materials, Datong 037009, China;
    2 School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China;
    3 Beijing Computational Science Research Center, Beijing 100084, China
  • 收稿日期:2023-07-07 修回日期:2023-10-06 接受日期:2023-10-09 出版日期:2023-12-13 发布日期:2023-12-13
  • 通讯作者: Peng-Bin Niu E-mail:niupengbin@163.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11834005).

Majorana tunneling in a one-dimensional wire with non-Hermitian double quantum dots

Peng-Bin Niu(牛鹏斌)1,† and Hong-Gang Luo(罗洪刚)2,3   

  1. 1 Institute of Solid State Physics, Shanxi Datong University, and Shanxi Provincial Key Laboratory of Microstructural Electromagnetic Functional Materials, Datong 037009, China;
    2 School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China;
    3 Beijing Computational Science Research Center, Beijing 100084, China
  • Received:2023-07-07 Revised:2023-10-06 Accepted:2023-10-09 Online:2023-12-13 Published:2023-12-13
  • Contact: Peng-Bin Niu E-mail:niupengbin@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11834005).

摘要: The combination of non-Hermitian physics and Majorana fermions can give rise to new effects in quantum transport systems. In this work, we investigate the interplay of PT-symmetric complex potentials, Majorana tunneling and interdot tunneling in a non-Hermitian double quantum dots system. It is found that in the weak-coupling regime the Majorana tunneling has pronounced effects on the transport properties of such a system, manifested as splitting of the single peak into three and a reduced 1/4 peak in the transmission function. In the presence of the PT-symmetric complex potentials and interdot tunneling, the 1/4 central peak is robust against them, while the two side peaks are tuned by them. The interdot tunneling only induces asymmetry, instead of moving the conductance peak, due to the robustness of the Majorana modes. There is an exceptional point induced by the union of Majorana tunneling and interdot tunneling. With increased PT-symmetric complex potentials, the two side peaks will move towards each other. When the exceptional point is passed through, these two side peaks will disappear. In the strong-coupling regime, the Majorana fermion induces a 1/4 conductance dip instead of the three-peak structure. PT-symmetric complex potentials induce two conductance dips pinned at the exceptional point. These effects should be accessible in experiments.

关键词: Majorana fermion, non-Hermitian quantum dot, parity—time symmetry, exceptional point

Abstract: The combination of non-Hermitian physics and Majorana fermions can give rise to new effects in quantum transport systems. In this work, we investigate the interplay of PT-symmetric complex potentials, Majorana tunneling and interdot tunneling in a non-Hermitian double quantum dots system. It is found that in the weak-coupling regime the Majorana tunneling has pronounced effects on the transport properties of such a system, manifested as splitting of the single peak into three and a reduced 1/4 peak in the transmission function. In the presence of the PT-symmetric complex potentials and interdot tunneling, the 1/4 central peak is robust against them, while the two side peaks are tuned by them. The interdot tunneling only induces asymmetry, instead of moving the conductance peak, due to the robustness of the Majorana modes. There is an exceptional point induced by the union of Majorana tunneling and interdot tunneling. With increased PT-symmetric complex potentials, the two side peaks will move towards each other. When the exceptional point is passed through, these two side peaks will disappear. In the strong-coupling regime, the Majorana fermion induces a 1/4 conductance dip instead of the three-peak structure. PT-symmetric complex potentials induce two conductance dips pinned at the exceptional point. These effects should be accessible in experiments.

Key words: Majorana fermion, non-Hermitian quantum dot, parity—time symmetry, exceptional point

中图分类号:  (Transport properties)

  • 74.25.F-
73.21.La (Quantum dots) 81.07.Gf (Nanowires) 73.23.-b (Electronic transport in mesoscopic systems)